COBRASConcrete Bridge Assessment Program

Welcome

Welcome to the COBRAS Concrete Bridge Assessment Program web site. This site
provides information about the program, and how it may be used to perform
yield-line analysis of concrete slab, and beam-and-slab bridges.

COBRAS is a yield-line analysis software program for assessing the
ultimate load capacity of concrete structures, and in particular, concrete
bridge decks.

A number of UK bridge authorities, consultants and overseas organisations
are currently using the program to evaluate the load carrying capacity of
concrete bridges that have failed assessment using conventional elastic
analysis methods.

The program has been developed in the Engineering Department at Cambridge
University by Dr Campbell Middleton and colleagues with support from various
bodies including the Highways Agency, Transport Research Laboratory (TRL)
and the Engineering and Physical Sciences Research Council (EPSRC). Over the
last ten years an extensive research programme has been undertaken to
validate the program's predictions.
This has included calibration with non-linear finite element analyses
undertaken in collaboration with the TRL and a series of tests on reinforced
concrete slab and beam-and-slab bridge models. In addition comparisons have
been made with the results from full-scale and model load tests and
theoretical studies that have been published in the literature.